1. Field of the Invention
The present invention relates to a heat exchanger for use as a radiator, a car heater, an intercooler or the like in automobiles or for other various uses.
2. Description of the Prior Art
In general heat exchangers for the uses mentioned above comprise tube elements which allow a heat exchanging medium to flow therethrough. The alloy "A3003" which is comparatively highly corrosion-resistant has been widely used to manufacture the tube elements in a case wherein water or any other corrosive heat-exchanging medium is employed as in radiators or the like. The known heat exchangers also comprise fin members which are secured to the tubular elements so as to raise the efficiency of heat exchange have been made of the same alloy "A3003".
There has been a problem that in the heat exchangers made of the alloy "A3003" the mechanical strength is often lowered for instance to about 4 Kgf/mm.sup.2 as a value of 00.2 (tolerable load), after the tubular elements and the fin members are soldered to each other. Thus, walls constituting the tubular elements and the fin members are usually made thicker to assure sufficient strength. This has led to a larger size, an excessive weight and a higher manufacture cost of the known heat exchangers. In addition, the sacrificial corrosion of the fin members made of the alloy "A3003" has been insufficient to protect the tubular element, thereby rendering the heat exchangers less resistant to corrosion.